/* RTL-based forward propagation pass for GNU compiler.
- Copyright (C) 2005-2014 Free Software Foundation, Inc.
+ Copyright (C) 2005-2018 Free Software Foundation, Inc.
Contributed by Paolo Bonzini and Steven Bosscher.
This file is part of GCC.
#include "config.h"
#include "system.h"
#include "coretypes.h"
-#include "tm.h"
-#include "diagnostic-core.h"
-
-#include "sparseset.h"
+#include "backend.h"
+#include "target.h"
#include "rtl.h"
+#include "predict.h"
+#include "df.h"
+#include "memmodel.h"
#include "tm_p.h"
#include "insn-config.h"
+#include "emit-rtl.h"
#include "recog.h"
-#include "flags.h"
-#include "obstack.h"
-#include "basic-block.h"
-#include "df.h"
-#include "target.h"
+
+#include "sparseset.h"
+#include "cfgrtl.h"
+#include "cfgcleanup.h"
#include "cfgloop.h"
#include "tree-pass.h"
#include "domwalk.h"
-#include "emit-rtl.h"
+#include "rtl-iter.h"
/* This pass does simple forward propagation and simplification when an
static vec<df_ref> reg_defs;
static vec<df_ref> reg_defs_stack;
+/* The maximum number of propagations that are still allowed. If we do
+ more propagations than originally we had uses, we must have ended up
+ in a propagation loop, as in PR79405. Until the algorithm fwprop
+ uses can obviously not get into such loops we need a workaround like
+ this. */
+static int propagations_left;
+
/* The MD bitmaps are trimmed to include only live registers to cut
memory usage on testcases like insn-recog.c. Track live registers
in the basic block and do not perform forward propagation if the
(DF_REF_PARTIAL | DF_REF_CONDITIONAL | DF_REF_MAY_CLOBBER)
static void
-process_defs (df_ref *def_rec, int top_flag)
+process_defs (df_ref def, int top_flag)
{
- df_ref def;
- while ((def = *def_rec++) != NULL)
+ for (; def; def = DF_REF_NEXT_LOC (def))
{
df_ref curr_def = reg_defs[DF_REF_REGNO (def)];
unsigned int dregno;
is an artificial use vector. */
static void
-process_uses (df_ref *use_rec, int top_flag)
+process_uses (df_ref use, int top_flag)
{
- df_ref use;
- while ((use = *use_rec++) != NULL)
+ for (; use; use = DF_REF_NEXT_LOC (use))
if ((DF_REF_FLAGS (use) & DF_REF_AT_TOP) == top_flag)
{
unsigned int uregno = DF_REF_REGNO (use);
public:
single_def_use_dom_walker (cdi_direction direction)
: dom_walker (direction) {}
- virtual void before_dom_children (basic_block);
+ virtual edge before_dom_children (basic_block);
virtual void after_dom_children (basic_block);
};
-void
+edge
single_def_use_dom_walker::before_dom_children (basic_block bb)
{
int bb_index = bb->index;
struct df_md_bb_info *md_bb_info = df_md_get_bb_info (bb_index);
struct df_lr_bb_info *lr_bb_info = df_lr_get_bb_info (bb_index);
- rtx insn;
+ rtx_insn *insn;
bitmap_copy (local_md, &md_bb_info->in);
bitmap_copy (local_lr, &lr_bb_info->in);
process_uses (df_get_artificial_uses (bb_index), 0);
process_defs (df_get_artificial_defs (bb_index), 0);
+
+ return NULL;
}
/* Pop the definitions created in this basic block when leaving its
{
case ASHIFT:
if (CONST_INT_P (XEXP (x, 1))
- && INTVAL (XEXP (x, 1)) < GET_MODE_BITSIZE (GET_MODE (x))
- && INTVAL (XEXP (x, 1)) >= 0)
+ && INTVAL (XEXP (x, 1)) < GET_MODE_UNIT_BITSIZE (GET_MODE (x))
+ && INTVAL (XEXP (x, 1)) >= 0)
{
HOST_WIDE_INT shift = INTVAL (XEXP (x, 1));
PUT_CODE (x, MULT);
- XEXP (x, 1) = gen_int_mode ((HOST_WIDE_INT) 1 << shift,
+ XEXP (x, 1) = gen_int_mode (HOST_WIDE_INT_1 << shift,
GET_MODE (x));
}
for a memory access in the given MODE. */
static bool
-should_replace_address (rtx old_rtx, rtx new_rtx, enum machine_mode mode,
+should_replace_address (rtx old_rtx, rtx new_rtx, machine_mode mode,
addr_space_t as, bool speed)
{
int gain;
eliminating the most insns without additional costs, and it
is the same that cse.c used to do. */
if (gain == 0)
- gain = set_src_cost (new_rtx, speed) - set_src_cost (old_rtx, speed);
+ gain = (set_src_cost (new_rtx, VOIDmode, speed)
+ - set_src_cost (old_rtx, VOIDmode, speed));
return (gain > 0);
}
{
rtx x = *px, tem = NULL_RTX, op0, op1, op2;
enum rtx_code code = GET_CODE (x);
- enum machine_mode mode = GET_MODE (x);
- enum machine_mode op_mode;
+ machine_mode mode = GET_MODE (x);
+ machine_mode op_mode;
bool can_appear = (flags & PR_CAN_APPEAR) != 0;
bool valid_ops = true;
*px = tem;
+ /* Allow replacements that simplify operations on a vector or complex
+ value to a component. The most prominent case is
+ (subreg ([vec_]concat ...)). */
+ if (REG_P (tem) && !HARD_REGISTER_P (tem)
+ && (VECTOR_MODE_P (GET_MODE (new_rtx))
+ || COMPLEX_MODE_P (GET_MODE (new_rtx)))
+ && GET_MODE (tem) == GET_MODE_INNER (GET_MODE (new_rtx)))
+ return true;
+
/* The replacement we made so far is valid, if all of the recursive
replacements were valid, or we could simplify everything to
a constant. */
}
-/* for_each_rtx traversal function that returns 1 if BODY points to
- a non-constant mem. */
+/* Return true if X constains a non-constant mem. */
-static int
-varying_mem_p (rtx *body, void *data ATTRIBUTE_UNUSED)
+static bool
+varying_mem_p (const_rtx x)
{
- rtx x = *body;
- return MEM_P (x) && !MEM_READONLY_P (x);
+ subrtx_iterator::array_type array;
+ FOR_EACH_SUBRTX (iter, array, x, NONCONST)
+ if (MEM_P (*iter) && !MEM_READONLY_P (*iter))
+ return true;
+ return false;
}
Otherwise, we accept simplifications that have a lower or equal cost. */
static rtx
-propagate_rtx (rtx x, enum machine_mode mode, rtx old_rtx, rtx new_rtx,
+propagate_rtx (rtx x, machine_mode mode, rtx old_rtx, rtx new_rtx,
bool speed)
{
rtx tem;
|| CONSTANT_P (new_rtx)
|| (GET_CODE (new_rtx) == SUBREG
&& REG_P (SUBREG_REG (new_rtx))
- && (GET_MODE_SIZE (mode)
- <= GET_MODE_SIZE (GET_MODE (SUBREG_REG (new_rtx))))))
+ && !paradoxical_subreg_p (mode, GET_MODE (SUBREG_REG (new_rtx)))))
flags |= PR_CAN_APPEAR;
- if (!for_each_rtx (&new_rtx, varying_mem_p, NULL))
+ if (!varying_mem_p (new_rtx))
flags |= PR_HANDLE_MEM;
if (speed)
between FROM to (but not including) TO. */
static bool
-local_ref_killed_between_p (df_ref ref, rtx from, rtx to)
+local_ref_killed_between_p (df_ref ref, rtx_insn *from, rtx_insn *to)
{
- rtx insn;
+ rtx_insn *insn;
for (insn = from; insn != to; insn = NEXT_INSN (insn))
{
we check if the definition is killed after DEF_INSN or before
TARGET_INSN insn, in their respective basic blocks. */
static bool
-use_killed_between (df_ref use, rtx def_insn, rtx target_insn)
+use_killed_between (df_ref use, rtx_insn *def_insn, rtx_insn *target_insn)
{
basic_block def_bb = BLOCK_FOR_INSN (def_insn);
basic_block target_bb = BLOCK_FOR_INSN (target_insn);
would require full computation of available expressions;
we check only restricted conditions, see use_killed_between. */
static bool
-all_uses_available_at (rtx def_insn, rtx target_insn)
+all_uses_available_at (rtx_insn *def_insn, rtx_insn *target_insn)
{
df_ref use;
struct df_insn_info *insn_info = DF_INSN_INFO_GET (def_insn);
rtx def_set = single_set (def_insn);
- rtx next;
+ rtx_insn *next;
gcc_assert (def_set);
\f
static df_ref *active_defs;
-#ifdef ENABLE_CHECKING
static sparseset active_defs_check;
-#endif
/* Fill the ACTIVE_DEFS array with the use->def link for the registers
mentioned in USE_REC. Register the valid entries in ACTIVE_DEFS_CHECK
too, for checking purposes. */
static void
-register_active_defs (df_ref *use_rec)
+register_active_defs (df_ref use)
{
- while (*use_rec)
+ for (; use; use = DF_REF_NEXT_LOC (use))
{
- df_ref use = *use_rec++;
df_ref def = get_def_for_use (use);
int regno = DF_REF_REGNO (use);
-#ifdef ENABLE_CHECKING
- sparseset_set_bit (active_defs_check, regno);
-#endif
+ if (flag_checking)
+ sparseset_set_bit (active_defs_check, regno);
active_defs[regno] = def;
}
}
I'm not doing this yet, though. */
static void
-update_df_init (rtx def_insn, rtx insn)
+update_df_init (rtx_insn *def_insn, rtx_insn *insn)
{
-#ifdef ENABLE_CHECKING
- sparseset_clear (active_defs_check);
-#endif
+ if (flag_checking)
+ sparseset_clear (active_defs_check);
register_active_defs (DF_INSN_USES (def_insn));
register_active_defs (DF_INSN_USES (insn));
register_active_defs (DF_INSN_EQ_USES (insn));
in the ACTIVE_DEFS array to match pseudos to their def. */
static inline void
-update_uses (df_ref *use_rec)
+update_uses (df_ref use)
{
- while (*use_rec)
+ for (; use; use = DF_REF_NEXT_LOC (use))
{
- df_ref use = *use_rec++;
int regno = DF_REF_REGNO (use);
/* Set up the use-def chain. */
if (DF_REF_ID (use) >= (int) use_def_ref.length ())
use_def_ref.safe_grow_cleared (DF_REF_ID (use) + 1);
-#ifdef ENABLE_CHECKING
- gcc_assert (sparseset_bit_p (active_defs_check, regno));
-#endif
+ if (flag_checking)
+ gcc_assert (sparseset_bit_p (active_defs_check, regno));
use_def_ref[DF_REF_ID (use)] = active_defs[regno];
}
}
uses if NOTES_ONLY is true. */
static void
-update_df (rtx insn, rtx note)
+update_df (rtx_insn *insn, rtx note)
{
struct df_insn_info *insn_info = DF_INSN_INFO_GET (insn);
performed. */
static bool
-try_fwprop_subst (df_ref use, rtx *loc, rtx new_rtx, rtx def_insn, bool set_reg_equal)
+try_fwprop_subst (df_ref use, rtx *loc, rtx new_rtx, rtx_insn *def_insn,
+ bool set_reg_equal)
{
- rtx insn = DF_REF_INSN (use);
+ rtx_insn *insn = DF_REF_INSN (use);
rtx set = single_set (insn);
rtx note = NULL_RTX;
bool speed = optimize_bb_for_speed_p (BLOCK_FOR_INSN (insn));
multiple sets. If so, assume the cost of the new instruction is
not greater than the old one. */
if (set)
- old_cost = set_src_cost (SET_SRC (set), speed);
+ old_cost = set_src_cost (SET_SRC (set), GET_MODE (SET_DEST (set)), speed);
if (dump_file)
{
fprintf (dump_file, "\nIn insn %d, replacing\n ", INSN_UID (insn));
else if (DF_REF_TYPE (use) == DF_REF_REG_USE
&& set
- && set_src_cost (SET_SRC (set), speed) > old_cost)
+ && (set_src_cost (SET_SRC (set), GET_MODE (SET_DEST (set)), speed)
+ > old_cost))
{
if (dump_file)
fprintf (dump_file, "Changes to insn %d not profitable\n",
making a new one if one does not already exist. */
if (set_reg_equal)
{
- if (dump_file)
- fprintf (dump_file, " Setting REG_EQUAL note\n");
+ /* If there are any paradoxical SUBREGs, don't add REG_EQUAL note,
+ because the bits in there can be anything and so might not
+ match the REG_EQUAL note content. See PR70574. */
+ subrtx_var_iterator::array_type array;
+ FOR_EACH_SUBRTX_VAR (iter, array, *loc, NONCONST)
+ {
+ rtx x = *iter;
+ if (SUBREG_P (x) && paradoxical_subreg_p (x))
+ {
+ set_reg_equal = false;
+ break;
+ }
+ }
+
+ if (set_reg_equal)
+ {
+ if (dump_file)
+ fprintf (dump_file, " Setting REG_EQUAL note\n");
- note = set_unique_reg_note (insn, REG_EQUAL, copy_rtx (new_rtx));
+ note = set_unique_reg_note (insn, REG_EQUAL, copy_rtx (new_rtx));
+ }
}
}
load from memory. */
static bool
-free_load_extend (rtx src, rtx insn)
+free_load_extend (rtx src, rtx_insn *insn)
{
rtx reg;
df_ref def, use;
reg = XEXP (src, 0);
-#ifdef LOAD_EXTEND_OP
- if (LOAD_EXTEND_OP (GET_MODE (reg)) != GET_CODE (src))
-#endif
+ if (load_extend_op (GET_MODE (reg)) != GET_CODE (src))
return false;
FOR_EACH_INSN_USE (use, insn)
/* If USE is a subreg, see if it can be replaced by a pseudo. */
static bool
-forward_propagate_subreg (df_ref use, rtx def_insn, rtx def_set)
+forward_propagate_subreg (df_ref use, rtx_insn *def_insn, rtx def_set)
{
rtx use_reg = DF_REF_REG (use);
- rtx use_insn, src;
+ rtx_insn *use_insn;
+ rtx src;
+ scalar_int_mode int_use_mode, src_mode;
/* Only consider subregs... */
- enum machine_mode use_mode = GET_MODE (use_reg);
+ machine_mode use_mode = GET_MODE (use_reg);
if (GET_CODE (use_reg) != SUBREG
|| !REG_P (SET_DEST (def_set)))
return false;
- /* If this is a paradoxical SUBREG... */
- if (GET_MODE_SIZE (use_mode)
- > GET_MODE_SIZE (GET_MODE (SUBREG_REG (use_reg))))
+ if (paradoxical_subreg_p (use_reg))
{
/* If this is a paradoxical SUBREG, we have no idea what value the
extra bits would have. However, if the operand is equivalent to
definition of Y or, failing that, allow A to be deleted after
reload through register tying. Introducing more uses of Y
prevents both optimisations. */
- else if (subreg_lowpart_p (use_reg))
+ else if (is_a <scalar_int_mode> (use_mode, &int_use_mode)
+ && subreg_lowpart_p (use_reg))
{
use_insn = DF_REF_INSN (use);
src = SET_SRC (def_set);
if ((GET_CODE (src) == ZERO_EXTEND
|| GET_CODE (src) == SIGN_EXTEND)
+ && is_a <scalar_int_mode> (GET_MODE (src), &src_mode)
&& REG_P (XEXP (src, 0))
&& REGNO (XEXP (src, 0)) >= FIRST_PSEUDO_REGISTER
&& GET_MODE (XEXP (src, 0)) == use_mode
&& !free_load_extend (src, def_insn)
- && (targetm.mode_rep_extended (use_mode, GET_MODE (src))
+ && (targetm.mode_rep_extended (int_use_mode, src_mode)
!= (int) GET_CODE (src))
&& all_uses_available_at (def_insn, use_insn))
return try_fwprop_subst (use, DF_REF_LOC (use), XEXP (src, 0),
/* Try to replace USE with SRC (defined in DEF_INSN) in __asm. */
static bool
-forward_propagate_asm (df_ref use, rtx def_insn, rtx def_set, rtx reg)
+forward_propagate_asm (df_ref use, rtx_insn *def_insn, rtx def_set, rtx reg)
{
- rtx use_insn = DF_REF_INSN (use), src, use_pat, asm_operands, new_rtx, *loc;
+ rtx_insn *use_insn = DF_REF_INSN (use);
+ rtx src, use_pat, asm_operands, new_rtx, *loc;
int speed_p, i;
- df_ref *use_vec;
+ df_ref uses;
gcc_assert ((DF_REF_FLAGS (use) & DF_REF_IN_NOTE) == 0);
/* In __asm don't replace if src might need more registers than
reg, as that could increase register pressure on the __asm. */
- use_vec = DF_INSN_USES (def_insn);
- if (use_vec[0] && use_vec[1])
+ uses = DF_INSN_USES (def_insn);
+ if (uses && DF_REF_NEXT_LOC (uses))
return false;
update_df_init (def_insn, use_insn);
result. */
static bool
-forward_propagate_and_simplify (df_ref use, rtx def_insn, rtx def_set)
+forward_propagate_and_simplify (df_ref use, rtx_insn *def_insn, rtx def_set)
{
- rtx use_insn = DF_REF_INSN (use);
+ rtx_insn *use_insn = DF_REF_INSN (use);
rtx use_set = single_set (use_insn);
rtx src, reg, new_rtx, *loc;
bool set_reg_equal;
- enum machine_mode mode;
+ machine_mode mode;
int asm_use = -1;
if (INSN_CODE (use_insn) < 0)
reg = DF_REF_REG (use);
if (GET_CODE (reg) == SUBREG && GET_CODE (SET_DEST (def_set)) == SUBREG)
{
- if (SUBREG_BYTE (SET_DEST (def_set)) != SUBREG_BYTE (reg))
+ if (maybe_ne (SUBREG_BYTE (SET_DEST (def_set)), SUBREG_BYTE (reg)))
return false;
}
/* Check if the def had a subreg, but the use has the whole reg. */
that isn't mentioned in USE_SET, as the note would be invalid
otherwise. We also don't want to install a note if we are merely
propagating a pseudo since verifying that this pseudo isn't dead
- is a pain; moreover such a note won't help anything. */
+ is a pain; moreover such a note won't help anything.
+ If the use is a paradoxical subreg, make sure we don't add a
+ REG_EQUAL note for it, because it is not equivalent, it is one
+ possible value for it, but we can't rely on it holding that value.
+ See PR70574. */
set_reg_equal = (note == NULL_RTX
&& REG_P (SET_DEST (use_set))
&& !REG_P (src)
&& !(GET_CODE (src) == SUBREG
&& REG_P (SUBREG_REG (src)))
&& !reg_mentioned_p (SET_DEST (use_set),
- SET_SRC (use_set)));
+ SET_SRC (use_set))
+ && !paradoxical_subreg_p (DF_REF_REG (use)));
}
if (GET_MODE (*loc) == VOIDmode)
forward_propagate_into (df_ref use)
{
df_ref def;
- rtx def_insn, def_set, use_insn;
+ rtx_insn *def_insn, *use_insn;
+ rtx def_set;
rtx parent;
if (DF_REF_FLAGS (use) & DF_REF_READ_WRITE)
if (forward_propagate_and_simplify (use, def_insn, def_set)
|| forward_propagate_subreg (use, def_insn, def_set))
{
+ propagations_left--;
+
if (cfun->can_throw_non_call_exceptions
&& find_reg_note (use_insn, REG_EH_REGION, NULL_RTX)
&& purge_dead_edges (DF_REF_BB (use)))
df_set_flags (DF_DEFER_INSN_RESCAN);
active_defs = XNEWVEC (df_ref, max_reg_num ());
-#ifdef ENABLE_CHECKING
- active_defs_check = sparseset_alloc (max_reg_num ());
-#endif
+ if (flag_checking)
+ active_defs_check = sparseset_alloc (max_reg_num ());
+
+ propagations_left = DF_USES_TABLE_SIZE ();
}
static void
use_def_ref.release ();
free (active_defs);
-#ifdef ENABLE_CHECKING
- sparseset_free (active_defs_check);
-#endif
+ if (flag_checking)
+ sparseset_free (active_defs_check);
free_dominance_info (CDI_DOMINATORS);
cleanup_cfg (0);
fwprop (void)
{
unsigned i;
- bool need_cleanup = false;
fwprop_init ();
for (i = 0; i < DF_USES_TABLE_SIZE (); i++)
{
+ if (!propagations_left)
+ break;
+
df_ref use = DF_USES_GET (i);
if (use)
if (DF_REF_TYPE (use) == DF_REF_REG_USE
|| DF_REF_BB (use)->loop_father == NULL
/* The outer most loop is not really a loop. */
|| loop_outer (DF_REF_BB (use)->loop_father) == NULL)
- need_cleanup |= forward_propagate_into (use);
+ forward_propagate_into (use);
}
fwprop_done ();
- if (need_cleanup)
- cleanup_cfg (0);
return 0;
}
RTL_PASS, /* type */
"fwprop1", /* name */
OPTGROUP_NONE, /* optinfo_flags */
- true, /* has_execute */
TV_FWPROP, /* tv_id */
0, /* properties_required */
0, /* properties_provided */
fwprop_addr (void)
{
unsigned i;
- bool need_cleanup = false;
fwprop_init ();
end, and we'll go through them as well. */
for (i = 0; i < DF_USES_TABLE_SIZE (); i++)
{
+ if (!propagations_left)
+ break;
+
df_ref use = DF_USES_GET (i);
if (use)
if (DF_REF_TYPE (use) != DF_REF_REG_USE
&& DF_REF_BB (use)->loop_father != NULL
/* The outer most loop is not really a loop. */
&& loop_outer (DF_REF_BB (use)->loop_father) != NULL)
- need_cleanup |= forward_propagate_into (use);
+ forward_propagate_into (use);
}
fwprop_done ();
-
- if (need_cleanup)
- cleanup_cfg (0);
return 0;
}
RTL_PASS, /* type */
"fwprop2", /* name */
OPTGROUP_NONE, /* optinfo_flags */
- true, /* has_execute */
TV_FWPROP, /* tv_id */
0, /* properties_required */
0, /* properties_provided */